Method of securing together pieces of stock



Nojv. 5, 1935. w ow 2,919,535

METHOD OF SECURING TOGETHER PIECES OF STOCK Filed Aug. 10, 1933 V fivvavma Wu 3m Patented Nov. 5, 1935 METHOD OF SECURING TOGETHER PIECES OF STOC Application August 10, 1933, Serial No. 684,554

28 Claims. (Cl. 12142) This invention relates to improvements in methods of securing together pieces of stock and is illustrated herein in connection with the manufacture of shoes.

In Letters Patent of the United States No.

1,970,257 for improvements in Methods of securing together shoe parts and the like, granted Aug.

14, 1934, on my copending application, I have disclosed the cement attachment of soles to shoe bottoms by means of cement formed by treating cellulose acetate fabric with a solvent which by acting on the fabric will produce cement, the shoe and sole being placed under pressure with the treated fabric between the sole and the shoe bottom.

5 As pointed out in the specification of said application, strands of yarn may be utilized as the source of the cement instead of woven or braided fabric.

In some of its aspects the present invention may be regarded as an improvement on the invention 20. of said copending application though in other aspects it is not necessarily to be so regarded.

Like the method of said patent, the present invention utilizes thread or yarn made at least in part of fibres composed of readily soluble material, for example a cellulose derivative such as a cellulose ester or ether, as a source of cement.

In accordance with the present invention stitching of thread composed of such soluble material is inserted in two or more pieces of stock which 30' are to be secured together or in stock which is to be cemented to other stock, the thread of the stitching being treated with a suitable solvent for the soluble material of the thread thereby cementing the stitching in place or forming 35 cement which may be utilized to secure the stitched piece of stock to another piece or both. I have disclosed the invention herein in connection with the performance of two different shoemaking operationsthe inseaming of welted shoes, particularly of welted shoes the outsoles of which are to be cement attached, and the cement attachment of soles to non-welted shoe bottoms. In the first case, a multi-strand thread, some of the strands of which are of a soluble cellulose derivative such as cellulose acetate While other strands are of relatively non-soluble material such as cotton or linen, is preferably utilized. If such a thread is passed through acetone or other solvent fcr the cellulose acetate immediately before the stitching is inserted, the cellulose acetate of the thread will be acted upon by the solvent forming a cement which is effective to cement the thread to the stock into which the stitching is inserted. Alternatively, such thread may be inserted dry and the solvent subsequently applied to the seam; or, if desired, solvent may be applied to the thread immediately before the stitching and additional solvent later applied to the stitches. Not only does this cement the stitches to the stock in which they are inserted, for example to 5 the welt, upper and insolelip of a shoe, but also, if the sole of the shoe is cement attached, the sole attaching cement will adhere strongly to the thread of the stitching thereby producing a more secure bond of the sole to the shoe bottom than 10 would be the case if an ordinary waxed thread were used.

In practicing my invention in the manufacture of non-welted shoes the marginal portion of a shoe upper may be quilted with a plurality of rows of stitching the major portion at least of the material of the thread of which is of soluble material, such as cellulose acetate, the stitching being inserted, for example, in the fashion disclosed in an application for Letters Patent of the United States Serial No. 601,372, filed March 26, 1932, in the name of James A. Cavanagh. Preferably, and in order to obtain a large amount of cement forming material on the surface of the shoe upper, a chain-stitch is employed with the double thread of the stitches on the exposed surface of the upper. After the shoe has been lasted, the quilted marginal portion of the upper, which lies flat against the insole in lasted position, is treated with a solvent for the material of the stitches 80 thereby forming cement. An outsole is positioned on the shoe bottom While the cement is still active and is held imder pressure while the cement is setting. If desired, the solvent with which the stitching is treated may contain dissolved cellulose esters or other material, for example as disclosed in Letters Patent of the United States Nos. 1,959,320 and 1,959,321, granted May 15, 1934, on applications filed in the name of Walter H. Wedger. 40.

In cement attaching soles to shoe bottoms in this way the usual roughem'ng of the overlasted marginal portions of the shoe upper is unnecessary since the needle holes formed during the stitching operation will be filled with cement and this will serve to insure a secure bond of the cement to the shoe bottom. Neither is itnecessary ordinarily to apply cement to the marginal portion of the sole before it is positioned on the shoe bottom though this may be done, if desired, without departing from my invention.

With the above and other objects in view of the invention will now be described with reference to the accompanying drawing and pointed out in the claims 1 ii In the drawing,

Fig. 1 is a fragmentary transverse section through the forepart of a shoe after the lasting operation;

Fig. 2 is a similar view, showing a portion of the shoe also in perspective, after the shoe has been welted;

Fig. 3 is a fragmentary transverse section through the completed shoe;

Fig. 4 is a somewhat diagrammatic view of a shoe upper the marginal portion of which has been quilted with stitching comprising thread composed of soluble material, for example cellulose acetate, a portion of the stitching being shown on an enlarged scale;

Fig. 5 is a fragmentary sectional view through a lasted shoe the upper of which has been quilted as in Fig. 4; and

Fig. 6 is a fragmentary transverse section through the shoe of Fig. 5 after its outsole has been cement attached.

In practicing the method of my invention in connection with the inseaming of a welt shoe, as illustrated in Figs. 1, 2 and 3, the shoe upper and insole .are first assembled and lasted in the usual manner. Thus Fig. 1 illustrates the shoe upper H] and an economy insole I2 assembled upon a last it, the marginal portion I6 of the upper being secured in lasted relation to a lip [8 of the insole 52 by staples 20 which may be inserted, for example, by a staple side lasting machine of the character disclosed in Letters Patent of the U nited States No. 1,796,451, granted Mar. 1'7, 1931, on an application filed in the name of George Goddu. The heel and toe portions of the upper may be lasted in any suitable or convenient manner, the details of which have nothing to do with the present invention, though the toe portion of the upper will naturally be brought into substantially the same relation to the lip [8 of the insole as that shown at the sides of the shoe in Fig. 1.

After the lasting operation, and after the trimming off of the excess upper material, the shoe is ready for the welting operation. As illustrated in Fig. 2, a welt 22 has been secured to the overlasted portion of the upper I and to the lip l8 of the insole i2 by an inseam 24 which, following practice usual in the manufacture of Goodyear welt shoes, comprises a chain-stitch seam with the double thread of the stitches lying in a shallow groove formed in the exposed surface of the welt 22. In accordance with the method of my invention and in order to cement the stitches into the leather of the shoe parts, the thread used for the inseam 24 comprises strands of soluble material, for example a cellulose ether or a cellulose ester such as cellulose acetate, which by treatment with a suitable solvent will form an adhesive well adapted to cement other insoluble strands of thread, composed for example of cotton or linen, to the material of the welt, the shoe upper and the lip of the insole. I may use, for example, a G-cord thread the fibre of two of the strands of which consists of cellulose acetate, available commercially under the name of Celanese, and the other four of which consist of cotton or linen. This thread may be passed through a solvent for cellulose acetate, for example acetone, immediately before it goes to the stitch forming mechanism or the solvent may be applied to the stitching after it has been inserted, or both. While the ordinary chain-stitch seam will easily rip and may be removed completely by pulling on the thread, .a chain-stitch seam formed as herein described is firmly anchored in the stock and cannot be removed by pulling on the thread after the solvent has had an opportunity to evaporate. Moreover, the thread of such a seam is in such a condition that pyroxylin cement, such as is used for cement attaching soles to shoes, will adhere tenaciously thereto. Accordingly, a seam of this character is a great improvement over the ordinary waxed thread seam if the outsoles of the shoes are to be cement attached. 0

Fig. 3 illustrates the shoe of Fig. 2, the outsole 26 of the shoe having been cement attached to the welt and the surfaces produced by the inseam trimming operation. It is to be understood, of course, that other usual shoemaking operations, which have nothing to do with the method of my invention, are performed in the completion of the shoe in any usual or desired fashion.

The application of my invention to another shoemaking operation is illustrated in Figs. 4, 5 and 6. The outer marginal portion of the materials of the shoe upper 30 of Fig. 4 is quilted, as illustrated at 32, by the insertion of a plurality of rows of stitching placed a short distance from each other and extending approximately parallel to the edge of the shoe upper and covering approximately the width of the lasting allowance thereof. Since this stitching is subsequently to be utilized as a source of cement by means of which an outsole is to be cement atttached, it is composed of thread consisting in whole, or at least in substantial part, of a soluble material adapted, by treatment with a solvent, to form cement. A heavy thread composed of cellulose acetate fibres is well adapted for this purpose and in order to provide a relatively large amount of cellulose acetate chain-stitch seams may be advantageously used with the chains of the seams on the outer surface of the shoe upper. The large number of needle holes formed in the layers of the upper 30 as this stitching is inserted constitute anchorages for the cement, which is later to be formed from the thread, and make it unnecessary to roughen the marginal portion of the upper as is usually done in the manufacture of compo (5 shoes after the lasting. Having this in mind, it will be understood that a short stitch is desirable and that the amount of cement supplied may be inscreased by using a relatively loose tension which will at the same time leave the thread in the condition in which it will most quickly soak up the solvent.

The shoe upper 36, as illustrated in Figs. 5 and 6, is secured in lasted relation to an insole 34 mounted on a last 36 by staples 38 which have been driven through the overlasted marginal portion of the upper into the insole, curving through the insole and being anchored therein without passing completely therethrough. Such staples may conveniently be inserted as a part of the side lasting operation by a machine of the character disclosed in Letters Patent of the United States No. 1,815,295, granted July 21, 1931, on an application filed in the name of George Goddu. The toe and heel portions of the upper may be lasted in any usual or desired manner. After any surplus upper stock has been trimmed ofi and a suitable bottom filler 39 and shank piece (not shown) applied the shoe is ready for the cement attachment of its outsole 40 (Fig. 6). The marginal portion of the outsole is roughened in a manner usual in the manufacture of compo shoes and the quilted overlasted marginal portion of the upper 30 is treated with a suitable solvent for the material of the thread. Acetone is a good solvent for cellulose acetate, cellulose nitrate and many other materials including generally the cellulose esters and ethers. Or I may use a solvent including dissolved material, such as high viscosity pyroxylin, as disclosed in Letters Patent of the United States'Nos. 1,959,320 and 1,959,321 previously referred to. After the solvent has had an opportunity to act on the material of the thread, and this will take only a fraction of a minute, the sole 4!] is) positioned on the shoe bottom and held under pressure in any suitable cement sole attaching machine while the cement is setting. While it is not ordinarily necessary to do so, I may coat the roughened marginal portion of the outsole with pyroxylin cement which is allowed to dry before the sole is attached. Such cement may be cut with a suitable softener, if desired, before the outsole is applied to the shoe bottom or sufiicient solvent may be applied to the stitching in the overlasted marginal portion of the upper so that the outsole may be applied to the shoe bottom without the application of softener to the cement on its marginal portion.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. That improvement in methods of securing together pieces of stock which comprises stitching the pieces of stock together with a thread composed at least in part of soluble fibres the material of which when dissolved is adhesive in character, and treating the thread with a solvent for said soluble material whereby the thread of the stitches is cemented in place.

2. That improvement in methods of securing together pieces of stock which comprises stitching the pieces together with thread at least part of the fibres of which are composed of a soluble cellulose derivative, and treating the thread with a solvent for said derivative whereby the thread of the stitches is cemented to the stock. 3. That improvement in methods of securing together pieces of stock which comprises stitching the pieces together with thread at least part of the fibres of which are composed of a cellulose ester, and treating the thread with a solvent for said cellulose ester whereby the thread of the stitches is cemented to the stock.

4. That improvement in methods of securing together pieces of leather which comprises stitching the pieces together with a thread composed at least in part of cellulose acetate fibre, and moistening the stitching with acetone whereby the thread is cemented to the leather stock.

5. That improvement in methods of securing together pieces of stock which comprises stitching the pieces of stock together with a thread. composed at l ast in part of fibres soluble in an organic solvent thereby forming cement, and treating the stitching with a solvent for the material of said soluble fibres thereby cementing the stitching in place.

6. That improvement in methods of securing together pieces of stock which comprises inserting stitching composed at least in part of fibres of soluble material which when dissolved is adhesive in character, and treating the stitching with a solvent for said soluble material whereby the stitching is cemented to the stock in which it is inserted.

'7. That improvement in methods of manufacturing shoes which comprises inserting stitching of thread at least part of the fibres of which are composed of a cellulose ester, and thereafter treating the stitching with'a solvent for said cellulose ester whereby the stitching is .cemented to the stock in which it is inserted.

3. That improvement in methods of manufacturing shoes which comprises inserting stitch- 5 ing of thread at least part of the fibres of which are" composed of a soluble cellulose derivative, and thereafter treating the stitching with a solvent for said cellulose derivative whereby the stitching is cemented to the stock in which it is inserted.

9. That improvement in methods of securing together pieces of leather which comprises stitching the pieces together with a thread at least part of thefibres of which consist of cellulose acetate, and thereafter treating the stitches with a solvent for cellulose acetate whereby the thread is cemented to the leather stock.

10. That improvement in methods of securing together pieces of stock which comprises treating thread composed at least in part of soluble fibres with a solvent which by acting on the material of said fibres will form cement, and immediately thereafter stitching the stock with said thread whereby the thread of the stitches is cemented in place.

11. That improvement in methods of securing together pieces of leather which comprises treating a thread at least part of the fibres of which are composed of a cellulose ester with a solvent therefor, and immediately thereafter stitching the pieces of stock together with said thread whereby the thread is cemented to the leather stock.

12. That improvement in methods of making shoes which comprises stitching. the marginal portion of a shoe upper with a thread composed at least in part of readily soluble material which upon treatment with a suitable solvent will form cement, treating the stitching with such a sol- 40 vent after the lasting of the shoe, thereby forming cement, and pressing a sole against the overlasted stitched marginal portion of the shoe upper.

13. That improvement in methods of making shoes which comprises stitching the marginal portion of a shoe upper with a thread composed at least in part of a readily soluble cellulose derivative, treating the stitching with a solvent for said cellulose derivative after the lasting of the shoe thereby forming cement, and pressing a sole on the shoe bottom.

14. That improvement in methods of making shoes which comprises inserting in the marginal portion of a shoe stitching a portion of the thread 5 of which lies on the surface of the upper, using a thread composed at least in part of a celluloseester, treating the stitching with a solvent for said cellulose ester after the lasting of the shoe thereby forming cement, and pressing a sole on the shoe bottom.

15. That improvement in methods of manufacturing shoes which comprises quilting the marginal portion of a shoe upper with a thread composed of soluble material which when treat- 05 ed with a suitable solvent will form cement, lasting the upper, treating the thread with which the marginal portion of the upper is quilted with such a solvent thereby forming cement, and pressing a sole against the shoe bottom while said cement is active.

16. That improvement in methods or manufacturing shoes which comprises quilting the marginal portions of a shoe upper forward of the heel breast line with a thread composed of a soluble cellulose derivative, thereafter lasting the upper, treating the thread with which the marginal portion of the upper is quilted with a solvent for said cellulose derivative thereby forming cement, and maintaining a sole pressed against the shoe bottom while said cement is setting.

17. That improvement in methods of manufacturing shoes which comprises stitching the marginal portion of a shoe upper with thread composed at least of a part of a cellulose ester, after the shoe has been lasted treating said sticthing with a solvent for said cellulose ester thereby forming cement, positioning a sole on the shoe bottom while the cement is active and holding it under pressure while the cement is setting.

18. That improvement in methods of manufacturing shoes which comprises stitching the marginal portion of a shoe upper with thread composed of cellulose acetate, after the shoe has been lasted treating said stitching with a solvent for cellulose acetate thereby forming cement, positioning a sole on the shoe bottom while the cement is active and holding it under pressure while the cement is setting.

19. That improvement in methods of manufacturing shoes which comprises inserting chain stitching of thread in the marginal portion of a. shoe upper with the double thread of the stitches on the outer surface of the shoe upper, said thread being composed of soluble material which upon treatment with a suitable solvent will form cement, after the shoe has been lasted treating the thread on the surface of the upper with such a solvent thereby forming cement, positioning a sole on the shoe bottom, and maintaining the shoe and sole under pressure while the cement is setting.

20. That improvement in methods of manufacturing shoes which comprises inserting chain stitching of cellulose acetate thread in the marginal portion of a shoe upper with the double thread of the stitches on the outer surface of the shoe upper, after the shoe has been lasted treating the thread on the surface of the upper with a solvent for cellulose acetate thereby forming cement, positioning a sole on the shoe bottom, and maintaining the shoe and sole under pressure while the cement is setting.

21. That improvement in methods of manufacturing shoes which comprises securing a welt to a lasted shoe upper and insole by an inseam at least part of the fibres of the thread of which are composed of soluble material which upon treatment with a suitable solvent will form cement, and treating the thread with such a solvent thereby forming cement and cementing the stitches in the shoe stock.

22. That improvement in methods of manufacturing shoes which comprises securing a welt to a lasted shoe upper and insole by an inseam the thread of which is composed at least in part I of soluble material which upon treatment with a suitable solvent will form cement, and there'- after treating the stitches of the inseam with such a solvent thereby forming cement and cementing the stitches to the shoe stock.

23. That improvement in methods of manu- -5 facturing shoes which comprises securing a welt to a lasted shoe upper and insole by an inseam the thread of which is composed at least in part of a cellulose ester, and cement-attaching the marginal portion of an outsole to the inseam and lasted shoe upper and insole by an inseam the 115 thread of which is composed at least in part of a cellulose ester, treating the thread with a solvent for the cellulose ester and thereby cementing the stitches to the shoe stock, and cement-attaching the marginal portion of the outsole to the inseam and the adjacent portions of the welt and the shoe bottom.

25. That improvement in the method of manufacturing shoes which comprises stitching a welt to a lasted shoe upper and insole by an inseam the thread of which is composed at least in part of soluble material which upon treatment with a suitable solvent will form cement, treating the stitching of the inseam with such a solvent, inseam trimming the shoe, and cement-attaching an outsole to the inseam, the welt and the surface produced by the inseam trimming operation.

26. That improvement in the method of manufacturing shoes which comprises stitching a welt to a lasted shoe upper and insole by an inseam the thread of which is composed at least in part of a soluble cellulose derivative, treating the stitching of the inseam with a solvent for said cellulose derivative, inseam trimming the shoe, and cement-attaching an outsole to the inseam, 4.9 the welt and the surface produced by the inseamtrimming operation.

27. That improvement in the method of manufacturing shoes which comprises attaching a welt to a lasted shoe upper and insole by an inseam 4.5 the thread of which is compose-d at least in part of a soluble cellulose derivative, inseam trimming the shoe and thereby removing the surplus stock adjacent to the inseam and providing the shoe with a substantially flat bottom, and cement-attaching an outsole to the inseam, the welt, and the adjacent surface produced by the inseam trimming operation.

28. That improvement in the method of manufacturing shoes which comprises attaching a welt to a lasted shoe upper and insole by an inseam the thread of which is composed at least in part of cellulose acetate, inseam trimming the shoe and thereby removing the surplus stock adjacent to the inseam and providing the shoe with a substantially fiat bottom, and cement-attaching an outsole to the inseam, the welt, and the adjacent surface produced by the inseam trimming operation.

MAX W. TETLOW. 

